Medium severity · published Apr 21, 2026
CVE-2026-40604
ClearanceKit: opfilter system extension can be suspended or signalled by a root process, disabling file-access policy enforcement
4.4
CVSS
0.1%
EPSS
No
On KEV
Description
ClearanceKit intercepts file-system access events on macOS and enforces per-process access policies. Prior to 5.0.6, the opfilter Endpoint Security system extension (bundle ID uk.craigbass.clearancekit.opfilter) can be suspended with SIGSTOP or kill -STOP, or killed with SIGKILL/SIGTERM, by any process running as root. While the extension is suspended, all AUTH Endpoint Security events time out and default to allow, silently disabling ClearanceKit's file-access policy enforcement for the duration of the suspension. This vulnerability is fixed in 5.0.6.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 1% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CL
clearancekit · craigjbass
< 5.0.6 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40604
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40604
Vendor Advisory
https://github.com/craigjbass/clearancekit/security/advisories/GHSA-5r9w-9fg6-266q
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